Metal chelates and process of preparing same



METAL CHELATES AND PROCESS OF PREPAG SAME Virgil W. Gash, Dayton, Ohio,assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation ofDelaware No Drawing. Filed May 9, 1956, Ser. No. 583,629

19 Claims. (Cl. 260-242) The present invention provides a new processfor the preparation of metal carbonyl complexes. The new processinvolves the treatment of a ,B-amino unfit-unsaturated carbonyl compoundwith a polyvalent metal ion, the amino group being cleaved from thecarbonyl compound, while the rest of the carbonyl compound forms acomplex with the metal.

The new process of my invention is represented by the equation:MXn-HzRC=CR1O-R+HzO- (RC=CR -CR)nM+nRNH.HX

N-R" o l R" I l in which M is a metal atom, n is an integer from 2 to 4,and X is a monovalent salt anion, R, R and R are organic radicals, e.g.,a-lkyl, acyl, alkoxy, aryl, aralkyl, aroyl, alkaryl, heterocyclic, orcycloaliphatic radicals, and R and R, can also be hydrogen and R" and Rare hydrogen or organic radicals, e.g., cycloaliphatic, acyl, alkyl,alkaryl, aryl, or aralkyl radicals, or R" and R together form aheterocyclic ring with the amino nitrogen atom. Of course, X can also bea divalent or trivalent salt anion in my process.

The present invention is also directed to a novel calcium chelate havinguseful gelling properties. Certain novel fi-amino a,fl-unsaturatedcarbonyl compounds and methods of making these compounds are alsodisclosed herein.

'It is an object of the present invention to provide a simple processfor preparing metal carbonyl complexes in purse form. It is also anobject to provide a process for preparing metal carbonyl complexes ingood yield with a short reaction time.

It isknown that certain metals, particularly multivalent heavy metals,.are capable of forming complexes or chelates With carbonyl compounds.However, prior art procedures for forming such complexes are notentirely satisfactory. The common procedure is to add a solution of asalt of a complex-forming metal to a solution of a 1,3-dicarbonylcompound, and then to add alkali solution in the amount required toneutralize the acid formed from the salt anion. This procedure issomewhat tedious clue to the care required in the neutralization step,and the dificulty sometimes encountered in washing the product free ofsalts. Prior procedures using buffering agents rather than alkali aresubject to similar difficulties.

i It has now been discovered that if the solution of a salt of acomplex-forming metal is reacted with a fi-amino mil-unsaturatedcarbonyl compound rather than with a 1,3-dicarbonyl compound, noneutralization or buffering step is necessary, and the desired metalcarbonyl complexes are formed rapidly and in good yield.

The following examples illustrate certain embodiments of my invention.

Example 1 t A solution of 25 grams of acetylacetone, 55 grams ofdiethylamine, and 0.5 gram of p-toluenesulfonic acid 2,976,285..Patented Mar. 21, 1961 monohydrate in 150 ml. of benzene was refluxedfor 4 hours. The colorless solution turned red, but no separation ofwater occurred. After distillation of the solvent, the residue wasdistilled at reduced pressure to yield 22.8 grams of a yellow oil.Redistillatiou through a 14-inch jacketed Vigreux column yielded 18.5grams (47.5%) of 4-diethylamino-3-penten-2-one, B.P. 80 C. 0.3 mm. Hg,11 1.5385, sp. gr. 0.938. This amino ketone is soluble in water and mostorganic solvents.

Analysis.Calcd. for C H NO C, 63.87; H, 8.93; N, 8.34. Found: C, 63.35;H, 8.68; N, 8.16.

A solution of 3.66 grams of the 4-diethylamino-3-penten-2-one in 10 ml.of water was added to a solution of 1.58 grams of cupric chloride in 10ml. of water. A blue precipitate formed immediately. After sittingovernight at 25 C., the mixture was filtered yielding 2.80 grams ofproduct, MP. 300 C. A small sample was recrystallized from ethanol toyield blue needles. The product was insoluble in water, but soluble indilute acid to give a colorless solution which turned blue upon additionof alkali.

Analysis.--Calcd. for C H CuO C, 45.88; H, 5.39. Found: C, 46.07; H,5.83.

Example 2 A solution of 25.8 ml. of acetylacetone and 65 ml. ofmorpholine in 200 m1. of benzene was refluxed for 20 hours while 6 ml.of water was collected. Solvent and excess morpholine were removed bydistillation and the residue was distilled at reduced pressure to give34.8 grams (82%) of 4-(N-rnorpholino)-3-penten-2-one, B.P. 10'5l10C./0.3 mm. Hg, Ml. 4648 C. This amino ketone is soluble in water and inmost organic solvents.

Analysis.Calcd. for C H NO C, 63.87; H, 8.93; N, 8.34. Found: C, 63.35;H, 8.68; N, 8.16.

Cupric chloride, 1.59 grams, and 4 grams of 4-(N-morpholino)-3-penten-2-one were reacted in a proceduresimilar to that ofExample 1 to yield 2.93 grams of a blue product identical in chemicaland physical properties to the acetylacetone-cupric copper complexobtained in Example 1.

Example 3 A solution of 2.61 grams (0.0168 mole) of4-diethylamino-3-penten-2-one in 10 ml. of water was mixed with asolution of 2 grams (0.0084 mole) of nickel chloride hexahydrate in 10ml. of water, After heating for 5 minutes, the blue-green crystallineproduct precipitated. Filtration gave 2.02 grams of product, 87.8% ofthe theoretical yield. Recrystallization from ethanol gave greencrystals, MP. 230 C. (decomposition).

Analysis.Calcd. for C H NiO -H O: C, 43.69; H, 5.87. Found: C, 44.09; H,6.24.

The compound lost its water of hydration when it was heated at to C.

Example 4 A solution of 25 ml. morpholine in ml. benzene was dried byazeotropic distillation. Then 21.73 grams (0.129 mole) ofacetyl-Z-thenoyl methane was added, followed by a trace ofp-toluenesulfonic acid hydrate. The solution was refluxed for 15 hours.The solution was evaporated on a hot water bath under water pump vacuum,and the residue cooled to a crystalline mass. A solution made up of 1part ether and 2 parts Skellysolve B (a petroleum ether) was added, andthe product was filtered out, 27.6 grams in amount, of M.P. 9098' C. Theproduct gave the following analysis:

Calcd for C H NO S: C, 60.73; H, 6.37; N, 5.90; S, 13.51.

Found: C, 61.15; H, 6.53; N, 5.70; S, 13.25. Ultraviolet analysis showeda max. at 258 mn witha shoulder at 280 my and also a max. of very highintensity" at about 355 m indicatin'g'tha't the structure was that of4-(N morpholino -4- (Z-th'ienyl) -3 -buten-2 one; "a posi tive iodoformtest confirmed this structure.

A..,solution of 2.37 grams (0.01 mole) ofthe above ketoenamine in 30 ml.ethanol was mixed with a solution 051.23 grams MgSO' 7H O' (0.005 mole)in 10ml. water. The reaction mixture was heated on a stea m bathandwater was added dropwise until the solution was completelyhomogeneous. The solution'stoo'd overnight, and the heavy' cream-coloredprecipitate wasthen filtered and washed with water. A small sample ofthe product left a white residue upon ignition. The product was solublein methyl alcohol, ethyl alcohol, acetone, and dimethyl'formamide,iand'insoluble in tertiary butyl alcohoLether, skellysolve Band ethyl acetate. Theprodnot was recrystallized from ethanolandwater'to give a cream-colored .material which melted 'at 260 C. withdecomposition. a

A nalysis.--Calcd. for C H MgO S C, 53.57; H, 3.93; Found: C, 53.35; H,4.54.

The infrared spectrum was of the type typical of metal chelates' of'unsaturated carbonyl compounds.

Thestructure ofthe compound can be represented by the following formula:

1 v r i on o-orn in. which the dotted lines represent co-ordinateco-valen'ce's." 1

Example A solution of 2.37 grams of 4-(N-morpholino-4-(2- thienyl)-3-buten-2-one'in 20 ml. ethanol was mixed with 0.85 gram CuCl -2H Odissolved in ml. of. 50:50

ethanol and water. solution-was produced, but, after several seconds, aprecipitate suddenly separated from the solution. The green precipitatewas filtered and dried to a weight of 1.91 grams, for a crude yield of96%. Recrystallization from ethanol-acetone and then fromethanol gavebright green shiny needles. When the needles were dried at 100 C.'/'0.3mm. there occurred a transition to a pale green amorphous state.Apparently the crystals are a hydrateor alcoholate. The melting point ofthe dried compound was 235-237 C. (dec.)'.

Infrared analysis showed the typical shift of'the carb'orlyl band tolonger wave lengths, i.e., at about 636 (1560 cm.' V

' "Aiziz'lysis'. -Calcd. for c n-I cums C, 48.29; H,

3.55. Found: .C, 48.38; H, 4.10.

' There was negligible absorption in the near infrared A. dark,completely homogeneous f1 "ism-ass, 7

30 seconds on a steam bath, and then water was added dropwise, causingprecipitation of a pale green product.

Further addition of water caused additional heavy precipitation. Theproduct was filtered, washed with water, and dried at 70 C. The driedproduct was recrystallized from methanol to give green crystals, ofmelting point llZ8 C. with foaming. "O'ne sample of the dried amor- 1phous product-waslfurther dried at 55" C./ 0.05 mm. over PCl to give aproduct 'melting'at 170 175 C. with decompositionlnfraredanalysis (ofthe 130 MP. sample} showed the absorption typicalofthis typemetal'chelate.

A broad intense band in the OH' region indicateda definite hydrate. Nearinfrared analysis (of the 170- 175 C. melting'producfi indicaaed'noappreciableabsorption at 08 A sample-of the crystalline material wasdried at 100 C./0.05 mm. over PCl to obtain a product melting at 173 C.with decomposition. This product gave the following analysis:

Calcdffor C H O SNi: C, 47.8; H, 3.5. Found: C, 48.57; H, 4.01.

This nickel chelate apparently exists in different states of hydration,depending upon the method of handling:

Example 7 A solution of 2.37 grams of 4 (N-'morpholii1o) 4-(2thie'nyD-B-buten-"Z-Qne was mixed with a solution of 0.88 gram Ni(OAc)in 10 ml. water. The product was precipitated, andworked'upas in theprevious example, to give a crude product melting at 128 C., and furtherproducts melting at 130 C., or 170-175 C., depending upon the method ofdrying. There was no depression. in meltingpoint when the 170-175 C.melting product was mixed with the corresponding product from Example-6, thereby indicating that'the anionic portion of the metal saltreactant has no important influence on the course of the'reaction;

Eranipl'e. 8

' A solution of 0.99 gram of-FeCl ll-i oin 5 mlkwater was mixed with asolution of 2.37 grams of 4-(N mortion was typical fora chelate of thistype.

'Example 9 7 v A solution of 2.37 grams (0.01 mole) 'of'4- (N-mor-'pholino)-4-(2-thienyl) -3-buten 2-one in 10 ml. ethanol mixed;..with asolution oi: 1.19 grams NiGl- 1 6H O in? 5 'mlioftwatem.Theareaction-,mixture.was warmed about was'r'nixed with a solution of:0.56 gram cacl (0.005 mole) in 5 ml. water and,5 ml. ethanol. Themixture was warmedv on a steam bath for 5 minutes, diluted to 50 ml.,and allowed to stand at room temperature. After about 15 minutescrystals began to separate. The mix turewas warmed again, diluted to150ml, and allowed to stand overnight. The precipitated crystals were removed by filtration, washed with distilled water, and dried at-70 C. togive 1.52 grams ofproduct as gold-' colored crystals.- Upon ignition,the material left a white residue. The'product was soluble in hotliquids such as' benzene, ether, chloroform, carbon tetrachloride andxylene, and the solutions-set to a gel upon cooling. The productWZiS'flCCIYSlfilllZCd.fZ'Ol'II aqueous ethanolto give gold-coloredleaflets whichsinter at 140 but do not completely melt untildecomposition at 270 C.

I The calcium, chelate, 50 mg, was heated, to boil-ingin 5 grams of Ybenzene, and then; cooled to. give -a solid;

immobile gel which did not flow when the container was inverted.

It appears that the calcium portion of the chelate is responsible forits gelling properties, as this same ligand has been used in thechelation of other metals and the chelates did not have the ability togel" organic solvents. The organic portions of the chelate can be variedconsiderably without destroying its gelling properties. In fact, theorganic portion can be varied to make the chelate applicable to thegelation of various solvents.

The calcium (2-thenoyl)acetonate gave negative tests for nitrogen andhalogen, and the following sulfur analysis:

Found: S,

V V 7 Example 10 A solution of 0.62 gram (1.67 mmoles) of A1(NO3)3'9H2Oin 10 ml. water was mixed with a solution of 1.19 grams rnmoles) of4-(N-morpholino)-4-thienyl-3-buten-2- one in 15 ml. warm ethanol. Acompletely homogeneous solution resulted, followed in about seconds by aheavy precipitate. The mixture was warmed on a steam bath for about 5minutes, diluted to 50 ml. with water, and kept at room temperature. Theprecipitate was filtered, washed with water, and air dried to give 0.79gram of yellow powder of MP. 235-8" C. (dec.). A sample wasrecrystallized from acetone-Skellysolve B solution, M.P. 233-237" C.(dec.).

Analysis.--Calcd. for (C3H7O2S)3A1: C, 54.53; H, 4.05. Found: C, 54.75;H, 4.53.

The compound is the desired trichelate of aluminum. Infrared analysiswas typical, i.e., the carbonyl bands were pushed to much longer wavelengths. The chelate can be represented by the following formula:

in which Example 11 Isonicotinoyl pivalyl methane, 8 grams, and 15 ml.of piperidine in 150 m1. of benzene containing a catalytic amount ofp-toluenesulfonic acid was refluxed for four hours. The solution wasevaporated under water pump vacuum to leave a residue which partiallycrystallized upon standing. The residue was distilled through a column,the fractions distilling at 92 to 100 C./ 0.1-0.2 mm. being collected.

Infrared analysis showed the typical shift of carbonyl absorption tolonger wave lengths.

A solution of 1.19 grams of CoCl -6H O in 5 ml. water and 5 ml. ethanolwas mixed with 2.72 grams of the 1- pivalyl-2(N-piperidyl) -2-('-pyridyl)ethylene. An orange precipitate separated immediately. Water,2.5 ml., was added to the reaction mixture, and the mixture was warmedon a steam bath for 10 minutes and filtered. The filtered solids werewashed with water and dried to 1.70 grams of yellow-orange powder, for ayield of 72.7%. The cobalt chelate product gave the following analysis:

Calcd. for C H N O Co: C, 61.66; H, 6.04; Co, 12.61. Found: C, 61.87; H,6.54; .Co, 12.45 (by residue).

6 Infrared analysis showed the typical lack of carbonyl bands, the firstband in this region occurring at 6.23 1 The chelate can be representedby the formula:

In aqueous ethanol solution, 4-(N-morpholino)-4-(2-thienyl)-3-buten-2-one was reacted with CoCl '6H O according to the'procedure of Example 6. A yellow- A solution of 2.78 grams ofbenzoyl-Z-furoly methane and 4 ml. piperidine in 60 ml. of dry benzenecontaining a catalytic amount of p-toluenesulfonic acid was refluxed for4 hours. The solvent was evaporated under vacuum and the thick, oilyresidue was crystallized to a solid mass. The crude product was taken upin hot Skellysolve B, and decanted from the tarry insoluble residue.Upon cooling, yellow crystals were obtained, and the crystals werefiltered, washed with Skellysolve B, and air dried, to give aB-(N-piperidino)-3-phenyl-1-(2-furyl)-2- propen-l-one product of MP.-406 C. (probably a cis-trans mixture).

A solution of 2.15 grams (0.00765 mole) of the above keto enamine in 15ml. ethanol was mixed with a solution of 0.52 gram (0.00382 mole) ZnClin 10 ml. water and 5 ml. ethanol, whereupon an instantaneousprecipitation occurred, to give a cream-colored product. The product wasfiltered, washed with water, and dried to 1.55 grams of the zincchelate, a lemon-colored solid. The chelate was recrystallized fromethanol to give lemonyellow crystals, which melted at -136" C., and thenpartially resolidified to again melt at about C.

Analysis.Calcd. for C H O Zn-L5H O: C, 60.19; H, 4.08. Found: C, 60.28;H, 4.08.

Infrared analysis indicated the hydrate form. The structure of the zincchelate can be represented by the Example 14 A solution of 50 grams ofacetylacetone in 250 ml. of benzene was refluxed to remove Water(Dean-Stark water trap). Then 50 grams of cyclohexylamine was addeddropwise at a sufiicient rate to maintain a gentle reflux. After 3hours, 8.3 ml. of water had separated. The solution was evaporated byheating under vacuum, leaving a mixture of oil and solid (possiblycistrans isomers). The product was distilled through a column to give86.4 grams of the 4-cyclohexylamino-3-penten-2-one, of refractive indexN 1.5315.

7 "'A'nalyszs'w-Calcd. for C H NO: C, 72.86; H, 10.56; N, -7.72. Found:C, 73.30; H, 10.70; N, 7.64.

Ultraviolet absorption showed amaximum .(ethyl alco= 1101) at 316 my,and infrared analysis indicated that the [Si-amino group had shifted thea,,8-urisaturated carbonyl bands to longer wavelengths, i.e., 6.15; and6.26 s.

A solution of 4-cyclohexylarnino3'-penten-2-one, 1.81 grams (0.01 mole),in 20 ml. ethanol was mixed with a solution of 0.85 gram (0.005 mole) ofCuC1 -2H O in ml. water. A brown solution was obtained which changed toa pale green colloidal (turbid) solution. The solution was heated on asteam bath and diluted to 50 ml. with water. After 5 to 8 minutesheating a blue, crystalline precipitate began to appear. The mixture washeated several more minutes, then allowed to stand overnight. Theprecipitate was filtered and washed with water to give 1.1 grams ofsilvery blue crystals ('not'com pletely dry). A sample wasrecrystallized from hot ethanol; the chelat'e changed to' a brownsolidat270 C. which does not melt up to 300 C Qualitative analysisindicated to'nitrogen or halogen in the chelate compound. Quantitativeanalysis of carbon and hydrogen showed:

Calcd. for C fi cuO z C, 45.88; H, 5.39. Found: C, 46.55; H, 5.95. i

The analyses indicate the cupric acetylacetonate, the same chelate aswas previously prepared by reaction of enamines containing diiierentamino groups. The infrared absorption spectrum was identical to thatobtained on the cupric acetylacetonate of Examples 1 and 2.

The above keto enamine failed to react with MgSO in aqueous ethanolafter several minutes heating on the steam bath. Dilution with 'watercaused separation of the oily enamine.

Example -M.P. 50-54 C. A sample was redistilledfor analysis,

B.P. 9c 91 c./0.2 mm. Hg, r. 51 4f c.

M33 314 u Y a g i Analy.ris;Calcd. for C H NO: C, 71.81; H, 10.01; N,8.38. Found; C, 71.91; H, 10.50; 131,81-46. a

Infrared analysis showed absorption bands in' theraiige 'Of 6.1--6.'2;r.j

Cupric acetylacetonate be formed from:this enamine byfollowingtheprocedure of Example 1..

It is well known that compounds containing the structure are capable ofexisting in tautomerie forms, such as the enol form andthat they willreact with metal salts "toform metal carbonyl complexes. A novel featureor my invention is't-h'e use or anamino group in place of the hydroxylgroup of the enol form, the amino group being capable of hydrolysis inthe presence of waterand themetal' salt to giv'e the" desired metalcarbonyl complex.

As knowntothose skilled in theart, the a boye 1,3 diearbonyljstructurecan have various types of organic I radicals as substituentswithoutdestroying its tauto nrerism orcomplex-formingability. Similarly,the fl-amino (1,18- unsaturated carbonyl compounds used in my processcan have various substituents, as illustarted-by the followingcompounds: 4 diethylamino-3-penten-2-one, 4-(N-morpholi'no) 3.-penten-Z-on'e, 4- (N-rnorpholino )'-4-(2-thienyl)- 3-117111611-2-0116',3= (N-piperidino -3 -phenyll- 2furyl) -2- propen-l-one, --4-(N-rno'rpholino) -4-(2=thienyl) =1-pheny-l- 3-buten- 2-one, .1-(N-morpholino) -l( Z-thienyl -4-ethoxyl-o'cten-3-one,' 4ethylmethylamino-4-acetyl-3-buten- 2 one, -4-,(N-anilino)-3-penten-2-one, 4-cyclohexylamino-3- penten Z-one,Z-(N-morpholino)-1-carbethoxy-1-propene, the N-piperidino derivative ofthe enol form of diethyl acetylmalonate, the N-morpholino derivative ofthe enol form of diethyl benzoyl malonate, Z-carbethoxy-l-(N-morpholino)-cyclohex-1-ene, 4-diphenylamino-5-phenyl 3 penten-Z-one,l-(N-morpholino)-l-penten-3-one, 4-amino 3-penten-2-one,4-di-(fi-hydroxyeth'yl)-amino-3- penten-2- one,4-(N-piper'idino)-4-(Z-thienyl)-1-trifiuoro-3-buten-2- one, etc.

The present process is particularly directed to'the for mation of metalchelates from B-amino a s-unsaturated ketones and esters. The ketonesand esters are usually more readily available than other B-aminou,B-unsaturated carbonyl compounds; moreover, these amino ketones andesters are not subject to tautornerization as are fi-aminoa,,B-unsaturated aldehydes when the amino group is secondary. Thesepreferred ,d-arnino u,fl-unsaturated ketones and esters=can berepresented by the formula:

Ro=oR1o-'-R' i in'which'R and R are any of the groups listed above withrespect to Formula I, except hydrogen, and R R", and R are'any' of thegroups listed above with respect to Formula I. The preferred [SJ-aminou,B-unsaturated ketones and esters are bases.

Although in its broadest aspects the process is applicable to fl-vaminoage-unsaturated carbonyl compounds in which the amino group is primary,secondary, or tertiary, it is very much preferred that the amino groupbe tertiary, i.e., that neither R" or R' in the formula above behydrogen. The useof a tertiary amino group insures a rapid, completereaction. When a secondary or primary amine is used, the reaction isslow and may not proceed at all with some metal salts; moreover, in somecases unwanted complexes may be produced in which the amino group isstill present on the carbonyl compound.

It;is ordinarily or no great importance which particular tertiary aminosubstituent is used, as the amino group is cleaved in my process anddoes not form part of the final chelate product. However, it isdesirable that the amino substituent be prepared from an inexpensiveamine, e.g. morpholi'ne-or piperidine. r The process" of the presentinvention is conveniently conducted: in-aqueous solution. Most of themetal salts arejsoluble in water, and few'of them are readily soluble inmanyother solvents. Some "of the B'-amino'u,B-unsaturated'carbohylTcomjadunds are fairly soluble'in water, and'the solubility of thecompoundscan be increased, if heces'sary,lby"the addition of an alcohol,-e.g., ethanol, methanol, n-propanol, isopropyl alcohol, etc. The metalchelate products are insoluble in water, and precipitate readily" fromaqueous solutions. gAlthou'gh aqueous solutions are the most convenientmedialforftlie'reactiomthe reaction can be conducted in othe'risuitablesolvents. -It.'is onlyne'cessary to select sol, vents which: willdissolve both the chosen flamino afiunsatui-ated licarbonyl"compound,and, the chosen'metal salt; .for "example, "cupriecl'il'oiride and 4'-(N-morpholino 4- (:2-thienyl) Q butenQ- 'ne are both fairly soluble inethyl alcohol; fiowever; even when .nonhquous solvents are used,water'will ordinarily-still bie' 'present in th'e reaction mixture,either because the selected solvent is not strictly anhydrous, orbecause the metal salt is hydrated.

The process of the present invention is applicable to a broad group ofchelate-forming metal ions. The metals are generally added to thereaction medium as a salt of some kind, or a solution of a salt, but thecharacter of the anionic portion of the salt is ordinarily of littleimportance, except for whatever effect it may have upon solubility inthe chosen reaction medium. Among the metal ions which will form thedesired chelates are Cu++, i++ c i++++ p H s Cr+++, etc.; some of themore preferred ions are Cu++, Mg+ Fe++, Ni++, Co++, Ca++, Zn++ andAl+++. The ions can be used in the form of their various salts; however,as aqueous solvents are ordinarily used, it is preferred to use saltswhich are fairly water soluble. Some of the preferred metal salts arethe chlorides, bromides, acetates (or salts of other organic acids), andin some cases, the sulfates and nitrates. Various other metal salts canalso be used, such as the carbonates, chlorates, percarbonates,arsenates, etc. Examples of a few of the applicable salts are cuprouschloride, magnesium sulfate, ferrous chloride, nickel chloride, nickelacetate, cobalt chloride, calcium chloride, zinc chloride, and aluminumnitrate.

It will be observed that most of the applicable metal ions have anatomic number of at least 20. .Moreover, most of the metal ions aredivalent or trivalent, the divalent ions being especially useful. Itwill also be noted that most of the ions are ions of metals which belongto the class of heavy metals (Langes Handbook of Chemistry, sixthedition, pages 59 and 60).

While the process is particularly directed to preparation of chelates ofsingle metals, it is also contemplated that mixtures of salts ofdiflerent metals can be used to prepare mixed chelate compositions.

While it is ordinarily preferred that the metal be in the form of a saltfor the reaction, it is also contemplated that part of the principalvalences of the metal can be satisfied by organic radicals, e.g., byhydrocarbon or substituted hydrocarbon radicals. As examples may bementioned such salts as dibenzyl tin dichloride, diethyl tin diacetate,diphenyl lead dibromide, etc. The use of these salts results in chelateproducts having principal valences satisfied by the organic radicals, aswell as the principal and co-ordinate valences satisfied by the chelategroups.

The metal salts and B-amino a,, 3-unsaturated carbonyl compounds can bereacted in various proportions to give the desired chelate products. Itis preferred to have approximately the stoichiometric amount of carbonylcompound required to satisfy all the ionic valences of the metal, i.e.,sufiicient to replace each anion of the salt with a chelate group. Iflesser amounts of the carbonyl compound are used, the same chelateproduct is produced, but all of the metal salt is not reacted; ifgreater amounts of carbonyl compound are used, the same product isobtained, but all of the carbonyl compound is not reacted. It isordinarily desirable to use about 0.5 to 1.5 stoichiometric equivalentsof fi-amino a,B-unsaturated carbonyl compound for each equivalent ofmetal salt.

The metal chelate products of my new process have many valuable uses,e.g., as polymerization catalysts, gelling agents, chemicalintermediates, semi-conductors, as the active ingredient ininsecticidal, fungicidal, or bactericidal compositions, as medicinal orpharmaceutical agents, as fuel additives, etc. My novel calcium (2-thenoyl)acetonate is especially useful as a gelling agent, particularlyfor organic solvents, and among the possible applications are asadditives in lubricating greases, printing inks and pastes, pastepolishes, paint removers, plastisols and plastigels, plastisol foams,etc. Moreover, as my process involves the chelation of metal ,ions byB-amino cap-unsaturated carbonyl compounds, it is evident that suchcarbonyl compounds are useful as metal scavenger agents, precipitants,etc. The li-amino 01,13- unsaturated carbonyl compounds can be added torubber compositions, fats and oils, gasoline, etc. as metaldeactivators. Traces of Cu, Co, Fe, etc. accelerate the aging of rubber,the development of rancidity in fats and oils, and the formation of gumsin gasoline, and the presence of small amounts of the fl-amino oe-unsaturated carbonyl compounds aids in retarding these reactions byrendering the metals inactive.

The structural formulae in the examples above are considered toberproperly representative of the chelate products of my process. Thedotted lines in the formulae are considered coordinate valences; suchvalences are indicated by the absence of normal carbonyl stretchingvibrations in the infrared region. However, I do not wish to be bound byany theory of the structure of the chelate product; regardless of whatthe structure of the productmay be, itis apparent that my processproduces a metal complex (metal enolate) of a 1,3-dicarbonyl compound,and that the amino group is cleaved during the reaction and does notappear in the product.

A method of preparing metal carbonyl complexes by the reaction offl-amino r p-unsaturated carbonyl compounds with polyvalent metal ionshas been described. The procedure is simple, gives good yields, andrequires only a short reaction time. The calcium chelate ofacetyl-2-thenoyl methane has been described. Certain novel ,B-arnino md-unsaturated carbonyl compounds and their methods of preparation havebeen described.

I claim:

1. A process for the preparation of metal complexes of diketones whichcomprises contacting a fl-amino 0:,5- olefinically unsaturated ketonewith a metal salt of a chelate-forming metal to produce a metal chelateof the diketone corresponding to the said ketone in which the saidp-amino group has been replaced by an oxygen atom.

2. The process of claim 1 in which the amino group of the ketone is atertiary amino group, and in which the metal salt with which thecompound is treated is a heavy metal salt.

3. A process for the preparation of metal complexes of diketones whichcomprises mixing a B-arnino 0a,,8- olefinically unsaturated ketone, thesaid ketone being hydrocarbon except for the keto oxygen and aminonitrogen, with a metal salt of a chelate-forming metal of atomic numberof at least 20 but no greater than 82 in aqueous solution, andseparating the resulting precipitate from the solution to obtain a metalchelate of the diketone corresponding to the said ketone in which thesaid fi-amino group has been replaced by an ox gen atom.

4. The process of claim 2 in which the fi-amino group is the morpholinogroup.

5. The process of claim 2 in which the amount of the metal salt isstoichiometrically equivalent to the amount of the ketone, in order tohave all the ionic valences of the metal satisfied by carbonyl complexlinkages.

6. A process for the preparation of metal chelates of carbonyl compoundswhich comprises contacting a 5- amino c p-unsaturated ketone, the saidamino group being tertiary, in aqueous solution with chelate-formingmetal ions of ionic valence from 2 to 3, about 0.5 to 1.5 stoichiometricequivalents of said unsaturated ketone being present for eachstoichiometric equivalent of metal ions to obtain metal chelates of thecorresponding diketones in which the said fl-amino has been replaced byoxygen.

7. The method of claim 6 in which the amount of ,8- aminoa,/8-unsaturated ketone is that stoichiometrically required to satisfyall of the ionic valences of the metal ions, and in which the metal ionswere formed by adding a water soluble metal salt.

8. The method of claim 6'in which the-metal ions are formed by addingcupric chloride. 7 p

9. The method of claim 6 in which the-metal ions, are formed by addingnickel chloride.

10. The method of claim 6 in unsaturated ketone is treated with ofcalcium chloride.

11. The method of claim 6 in -which the, said 1, 3- unsaturated ketoneis treated withan aqueous solution of cobaltous chloride.

12. The method of claim 6 in unsaturated ketone is treated with of zincchloride.

which. thesaid 11,5- an aqueous solution which: the said a,,B- anaqueous solution 13. The method of claim 6 inawhich the saidnapunsaturated ketoneis treated with an aqueoussolution of aluminumnitrate. a e

1,4. The method of claim 6 in which the fie'amino afiunsaturated ketoneis a fi-amino-3 penten-2-one.-

15. The method of claim 6 in whichthe fi-aminogroup is the morpholinogroup. V a

16. The method of claim 6 in which the *B-amino 3- unsaturated ketone is1-pivalyl-2-(N-piperidyl)-2-('y-pye ridyl)ethene. 7 17. As a newcompound, the calcium chelate of: acetyl. Z-thenoylmethane.

18'. A process for the preparation of metal chelatesof diketones whichcomprises contacting a fi-amino 0;, 3- unsaturated ketone, the saidamino'group being tertiary and the said ketone being hydrocarbonexceptfor the keto oxygen and the amino nitrogen, inaqueoumsolution'with water soluble ions of metals selected from the; group 12 consistingof copper, magnesium, iron, nickel, cobalt, ca1cium,-titanium,manganese, zinc, aluminum, tin, antimony, lead, mercury, barium,strontium, andtchromium, about 0.5 to 1.5 stoichiometric equivalentsofsaidunsaturated ketone being'present for each stoichiometricequivalent of metalions, to obtain a metal chelate oflthediketonecorrespbnding to the saidketone in which the said fl-aminogrouphas been replaced by an oxygen atom. 19. A method of preparing thecalcium chelate of acetyLZ-thenoylmetham which comprises warming over asteam bath an aqueous mixture consisting of Water, 4-

(N-morpholino v4- 2-thieny1) -3 -buten-2-0ne and calcium chloride toobt'ainthefsaid calcium uchelate.

References Cited in the file of this patent V UNITED STATES; PATENTS2,278,965 1Van:Peski' :Apr.7, 1942.

? FOREIGN PATENTS France Jan.'13, 1954 OTHER I REFERENCES" Cromwelletal;,: Journal of Organic Chemistry, vol. 14(1949), pp. 4'l1 -420.

Berg-etaL: Analytical Chemistry, vol. 27, July 1955, pp. 1131-1134.

Harris et al J0u1-nal American Chemical Society, vol. 70, October 1948,pp 3360-8361.

Reid et -a1. Journal American Chemical Society, vol. 72, July 1950 pp.2948-2952.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0 2 976285 March .21 1961 Virgil W8 Gash It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column l line 45 for purse read pure --3 column, 7 line 21 for "to" readno Signed and sealed this 21st day of May 1963.

(SEAL) Attest:

ERNEST w. SWIDER DAVID L- L Attesting Officer Commissioner of PatentsUNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,,976285 March 2 1 1961 Virgil Wa Gash It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as' corrected below.

Column l line 45 for "purse" read pure --3 column 7 line 21 for "to"read M no Signed and sealed this 21st day of May 1963.

(SEAL) Attest:

ERNEST w. SWIDER VID L- L D Attesting Officer Commissioner of Patents

1. A PROCESS FOR THE PREPARATION OF METAL COMPLEXES OF DIKETONES WHICHCOMPRISES CONTACTING A B-AMINO A,BOLEFINICALLY UNSATURATED KETONE WITH AMETAL SALT OF A CHELATE-FORMING METAL TO PRODUCE A METAL CHELATE OF THEDIKETONE CORRESPONDING TO THE SAID KETONE IN WHICH THE SAID B-AMINOGROUP HAS BEEN REPLACED BY AN OXYGEN ATOM.